Strutless type umbrella

ABSTRACT

Umbrella rib assembly is presented for use in strutless umbrella having a pin and slide canopy conducting mechanism. The rib assembly comprises a longitudinal rib body having a pivot member at its end, and a rib lever extending from the rib body, and being characterized in that the pivot member and the rib body together with the rib lever present a single piece of material, and the pivot member is located in a corner formed between the rib body and the rib lever.

FIELD OF THE INVENTION

This invention is generally in the field of umbrellas, and relates to sstrutless-type umbrella.

BACKGROUND OF THE INVENTION

Up to date most if not all umbrellas in the market make use of strutsextending between the umbrella stick and the canopy for supporting thecanopy ribs at some mid portion thereof. Strutless umbrellas (i.e.having a canopy without stretchers extending between the umbrella postand the ribs) are known in the patent literature, and are described forexample in the following patents:

U.S. Pat. No. 5,711,234 discloses a strutless umbrella which includes acentral post, either an inner plunger or tube, a canopy assemblyincluding ribs pivotally mounted on the upper end of the central post.Links connect the ribs to the inner plunger or tube. Movement of one ofthe ribs moves the plunger or tube which moves the remaining ribs. Alatch pin holds the umbrella in the open position.

U.S. Pat. No. 5,638,846 discloses an umbrella having a simplifiedconstruction which dispenses with the stretcher members (struts) ofconventional umbrellas and has one end hinged to the central portion ofeach rib. Said umbrella includes a runner axially slidable along theumbrella pole between a folded position in which the ribs can be foldedagainst the pole, and an unfurled position in which the runner engagesthe ribs and holds them in the extended position. For this purpose, therunner comprises an upper frusto-conical portion engageable with theends of the reinforcing portions of the ribs. It can be appreciated thataccording to U.S. Pat. No. 5,638,846, the ribs are to be folded bygravity acting on their own weight, since there is no user activatedmechanism for folding them.

AT 231634 discloses strutless umbrella aimed at protecting fromradioactive rain following nuclear disaster. The umbrella ribs extendinto the umbrella crown into which being incorporated a guiding deviceplaced inside the stick tube and operable from the umbrella's handle.The guiding device comprises an actuation rod passing upwardly throughthe stick tube, and a grooved plate mounted on the rod. The center endsof the canopy ribs formed in the shape of spheres enter the groovedplate. Above the plate, a pressure spring is mounted on the actuationrod and supported on its next end in the stick head which is mounted onthe umbrella crown.

Other strutless umbrellas, developed by the inventor of the presentapplication, utilize a canopy conducting mechanism, which may be usefulfor electrical umbrellas. The canopy conducting mechanism has shortmovement between open and closed states of the umbrella and is based onpin and slide joints between the umbrella ribs and between a canopyconducting member.

Needless to say that the appearance of strutless umbrellas is neater andmore elegant when compared to that of umbrellas having struts.Furthermore, strutless umbrella enables a user to bring the canopy veryclose above his head, which may improve the protection the umbrellaprovides, especially in hard and windy weather conditions.

SUMMARY OF THE INVENTION

There is a need in the art to improve a canopy conducting mechanism ofstrutless umbrellas. This is associated with the following:

One problem that should be addressed when designing a strutless umbrellais the dimensions of the umbrella in its folded state, which shouldpreferably not significantly exceed those of the conventional umbrellas(with struts). It will thus be advantageous to have a canopy deploymentand closing mechanism providing for substantially regular diameter (thatof the conventional umbrella) of the folded strutless umbrella. Itappears that it is not simple to comply with this requirement.

Reduction in the weight of umbrellas, whether or not they are strutless,will also be welcomed by users. The motivation of umbrella designers toreduce the number and weight of umbrella components is thereforeacknowledged. Moreover, this should be done without significantlyaffecting umbrella's strength, durability, and fitness to comply withintense winds.

As mentioned above, strutless umbrellas have no struts to help inlifting and lowering the ribs between deployed and closed states of theumbrella. Considering for example the above-mentioned patents, thefollowing should be noted:

The umbrella of U.S. Pat. No. 5,638,846, having no struts, leaves thecontrol on folding the canopy to the gravity force acting on it.

According to AT 231634 and U.S. Pat. No. 5,711,234, the mechanisms forpivoting the ribs for lifting or lowering them are based on pushing andpuling them through an extension of the rib body made between theirpivot axis and the area above the top of the stick. Therefore, in thesemechanisms the length of the extension of the ribs together with thedimensions of other parts of the mechanisms located above the top of thestick define a minimum to the possible diameter of the folded umbrella.Since said extension of the rib acts as a lever arm, it can beappreciated that the forces acting on both the extension and the pivotalconnection of the rib are in an inverse relation to the length of theextension. The longer the extension is, the lower the acting forces are,and vice versa. Therefore, in order to reduce the acting forces, thelever arms should be extended respectively, resulting in enlargement inthe diameter of the folded umbrella.

Referring to AT 231634, it is to be noted that the minimum diameter ofthe folded umbrella is the distance measured between the bent corners oftwo opposite ribs. This minimal diameter would be about 130% of thecrown's diameter. Also, the diameter of the actuation rod together withtwice the wall thickness of the grooved plate adds to the lengths of twoopposite rib extensions from pivot pin to sphere in defining a minimumpossible diameter of the crown. It is further to be noted that thecontact area between the plate and the ends of the ribs is pointed,since it is the area between a flat surface of the plate tangential tothe sphere. As the acting forces are high, pressure between the surfacesbecomes extremely high, which may result in accelerated wearing of boththe surface of the plate and the spheres. The diameter of the pivot pinis about only 5% of the lever arm (i.e. the distance from the pivot pinto the sphere). Accordingly, the contact area between the pin and theapertures in which it pivots is very small, and thus the pressurebetween the contacting surfaces of the pin and the apertures will behigh, causing accelerated wearing of the pivot connection.

The present invention solves the above problems by providing a novelconfiguration of a rib assembly for strutless umbrella (having a pin andslide canopy conducting mechanism), enabling reduction of the umbrelladiameter when in its folded state. This is achieved by providing atleast one of the following configurations of the rib assembly comprisedof a longitudinal rib body having a pivot member at its end, and a riblever extending from the rib body: (i) the pivot member is located in acorner formed between the rib body and the rib lever; (ii) the rib leverextends from the rib body in an angle of between 110-160 degrees; (iii)the rib lever has a goggles shaped profile; (iv) the height of the ribbody is similar to the max distance between the round surfaces of therib lever; (v) the max thickness of the rib lever is certainly smallercomparing to the max distance between the rounded surfaces of the riblever; (vi) the round sliding surfaces of the rib lever aresubstantially planner in a direction parallel to a pivoting axis of therib; (vii) the pivot member is formed as a pair of lateral protrusionsprotruding from the pivot point to form a pivoting axis from the samepiece of material of the rib; (viii) the distance between the pivotmember and the free end of the rib lever does not exceed about 200% ofthe max distance between the round surfaces of the rib lever; (ix) thefree end of the rib lever has a coin shape tapering towards the freeend; (x) the free end of the rib lever has a coin shape truncated at thefree end; (xi) the pivot member has a diameter greater than about 20% ofthe rib lever's length.

According to one broad aspect of the invention, there is provided anumbrella rib assembly for use in strutless umbrella having a pin andslide canopy conducting mechanism, the rib assembly comprising alongitudinal rib body having a pivot member at its end, and a rib leverextending from the rib body, and being characterized in that the pivotmember and the rib body together with the rib lever present a singlepiece of material, and the pivot member is located in a corner formedbetween the rib body and the rib lever.

The material of the pivot member and the rib body may be a polymericmaterial.

Preferably, the rib lever extends from the rib body in an angle ofbetween 110-160 degrees. The rib lever may have a goggles shapedprofile. The rib lever preferably has rounded upper and lower slidingsurfaces, with the height of the rib body being similar to a maximaldistance between said rounded surfaces. The maximal thickness of the riblever is preferably smaller as compared to a maximal distance betweenthe rounded upper and lower sliding surfaces of the rib lever. Therounded surfaces are preferably substantially planner in a directionparallel to a pivoting axis of the rib assembly.

Preferably, the pivot member is formed as a pair of lateral protrusionsprotruding from a pivot point to form a pivoting axis from the samepiece of material. A distance between the pivot member and the free endof the rib lever preferably does not exceed about 200% of the maximaldistance between round upper and lower sliding surfaces of the riblever.

Preferably, the configuration is such that the free end portion of therib lever has a coin shape tapering towards the free end of the riblever, or a coin shape truncated at the free end of the rib lever. Thediameter of the pivot member is greater than about 20% of the riblever's length.

According to another aspect of the invention, there is provided astrutless umbrella comprising a plurality of the rib assemblies, eachconfigured as described above.

Each of the rib assemblies is preferably pivotally mounted in a housinghaving a base part connected on top of the umbrella's stick and a cappart secured on top of the base part. A corresponding number of pairs ofrecesses is provided between the base part and the upper part, each pairof recesses accommodating a pivot axis of one of the rib assemblies.

Preferably, the free ends of the rib levers are located between upperand lower restricting members forming a slide in which rounded upper andlower surface of the rib levers can slide when the rib assemblies areforced to pivot upon a linear movement of the slide in line with thelongitudinal axis of the umbrella. The upper and lower restrictingmembers are secured to each other and to the upper edge of a rod passingthrough the stick, by means of a screw. Preferably, a distance betweenthe round surfaces of the rib lever is greater than a distance betweenslides which serve mirroring ribs. The rib assemblies preferably havegradually reduced thickness towards their distal ends resulting inflexibility of the ends of the rib assemblies useful for obtainingmushroom shaped canopy.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to understand the invention and to see how it may be carriedout in practice, preferred embodiments will now be described, by way ofnon-limiting example only, with reference to the accompanying drawings,in which:

FIGS. 1A to 1C illustrate, in partial vertical cross section view, threestates during the operation of a canopy conducting mechanism of thepresent invention based on pin and slide joint;

FIG. 2 illustrates a partial lateral cross section view of the canopyconducting mechanism in its state of FIG. 1B;

FIG. 3 illustrates a side view of an umbrella rib according to theembodiment of FIGS. 1A to 2, made of one piece of material;

FIG. 4 illustrates a top view of the canopy rib of FIG. 3;

FIG. 5 illustrates another embodiment of an umbrella rib according tothe present invention;

FIG. 6 illustrates the rib of FIG. 5 with the free end of its rib leversituated in a canopy conducting member;

FIG. 7 illustrates another embodiment of a rib according to the presentinvention;

FIG. 8 illustrates a top view of the ribs and the base part of thehousing in the embodiment of FIG. 7;

FIG. 9 illustrates an isometric view of a cap of a rib housing, to bemounted on a base part;

FIG. 10 illustrates an isometric view of the base part of the embodimentof FIG. 8; and

FIG. 11 illustrates in isometric another embodiment of a two-parthousing connected on top of an umbrella stick.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Referring to FIGS. 1A-1C and 2, there is illustrated an example of acanopy conducting mechanism of the present invention, which in thepresent example is based on a pin-and-slide joint. The latter is of thetype defining an elongated contact region between a pin (i.e., acylindrically-like element with circular or other rounded base surfaces)and a slide plane, the contact region thus being a line along thecylinder-like generator. FIGS. 1A-1C show, in partial vertical crosssection view (taken at A-A of FIG. 2), three operational states,respectively, of the mechanism, and FIG. 2 shows a partial lateral crosssection view (taken at B-B of FIG. 1B) of the canopy conductingmechanism in its state of FIG. 1B.

In the illustrated embodiment, a pin 300 of the pin-and-slide joint isactually the end portion of a rib lever 303 of an umbrella rib body 301.Pin 300 is also referred to in the context of the present invention as“the free end of the rib lever”. In this example, pin 300 has acoin-like shape, i.e. a cylinder of a relatively small height, namelyhaving a diameter significantly larger than its thickness (measuredperpendicular to the figure plane), and is tapered toward the free endof the pin. This feature can be seen clearly in FIG. 2. The pin 300 ismounted for sliding movement along a hollow cell 311 (will be referredto also as “slide 311”) made in a canopy conducting member 310, whichactually is a hub comprising a plurality of such hollow cells 311arranged in a spaced-apart radial array about a common center.

In FIG. 1A, the canopy conducting member 310 is shown in its uppermostposition above the umbrella stick (not illustrated), with the pin 300forcing the rib lever 303 upwards, thus keeping the rib body 301downwards, which corresponds to a closed canopy state. When the canopyconducting member 310 moves down to the position illustrated by FIG. 1B,it forces the free end of the rib lever downwardly and furthermore toslide inwardly inside the hollow cell 311, thus forcing the rib body 301to rotate upwardly about the pivot member 302, to a mid position whichcorresponds to a partially open state of the canopy. By further loweringthe canopy conducting member 310 to the lowermost position, asillustrated by FIG. 1C, the free end of the rib lever is forceddownwards and laterally outwards from the hollow cell 311, thus forcingthe rib body 301 to further pivot about the pivot member 302, to theposition which corresponds to the open state of the umbrella. As can beappreciated, the pin-and-slide joint formed by the free end (“pin”) 300and slide 311 allows to convert the up-down vertical movement of theconducting member 310 into a pivoting movement of the lever 303 and therib body 301 about the pivot member 302. It is appreciated that the riblever 303 may be designed shorter than illustrated, and actually thefree end (pin) 300 itself may function as a rib lever.

As shown in FIG. 2, in the state illustrated by FIG. 1B, the ribs 301are in a mid location with the canopy partially opened and with the freeend 300 of each rib lever 303 being maximally slid along the slide 311in the direction of the central axis of the conducting member 310. Thisis in contrast to what is shown in FIGS. 1A and 1C in which the free end300 of the rib lever reaches its maximal opposite slid along the slide311, i.e. its max distance from the center of the conducting member 310.The up-down movement of the conducting member can be achieved by a hubextension 312 (shown in FIGS. 1A-1C) extended into the stick of theumbrella.

Reference is made to FIGS. 3 and 4 illustrating side and top views,respectively, of an umbrella rib assembly according to theabove-described embodiment of FIGS. 1A to 2, and made of one piece ofmaterial. The rib assembly can be produced from plastic casting, as one(integral) unit comprising rib lever 303 and its free end 300, pivotmembers 302 from both rib's sides, and rib body 301. The rib body 301itself may have recesses 304 from both its sides, thus reducing itsweight with negligible lose of strength. The opposite end portion 305 ofthe rib body 301 can be made gradually tapered, such that its thicknessat the end of the rib body 301 is sufficiently reduced as to make itflexible. As a result, when the canopy is fully opened the rib body 301is forced to the arched shape illustrated by doted line 306, due to astress exerted by the canopy fabric (not illustrated) which isdimensioned and designed in a mushroom shape, forcing the flexible endsof the rib bodies to bent downwardly. The stress exerted by the canopyfabric significantly increases the forces acting on the rib lever 303,on the pivot member 302, and significantly increases the pressure in thetangential contact between the round surfaces of the coin shaped freeend 300 and the surfaces of the slide 311. However, the above-describedumbrella rib construction includes several features which allow it tocomply with extreme acting forces: the rib assembly has a pivoting axisdefined by the pivot member 302 having a diameter greater than about 15%of a distance between it and the central axis of the coin shaped “pin”300, and is furthermore integral (made from the same piece of material)to the rib body. The tangential contact between the round surfaces ofthe coin shaped “pin” 300 and the surfaces of the slide 311 is linearand not pointed, The rib assembly has a massive lever structure 303having a height (measured in the figure plane perpendicularly to thelongitudinal axis of the lever arm) averagely greater than half itslength and twice its width. As shown in FIG. 4, the rib assembly hasflat end 305 which is flexible in the direction perpendicular to theillustration plane, due to reduced thickness of the end of the rib body.

Accordingly, the present invention provides an umbrella having a canopyconducting mechanism described above, wherein the rib bodies are made ofa rigid material and have gradually reduced thickness at their distalends resulting in flexibility thereof useful for obtaining mushroomshaped canopy.

Referring to FIG. 5, there is illustrated another embodiment of anumbrella rib 1 according to the present invention. The figure focuses onthe area of a rib lever 3 and its meeting area with a rib body 5. Therib lever extends from the rib body in an angle A. This angle is in therange of between 110-160 degrees, and is preferably about 135 degrees. Apivot member 2 is located in a corner 4 formed between the rib body 5and the rib lever 3. The rib lever 3 has a goggles shaped profile. Thisis identifiable by a valley 6 formed between two hills 6 a and 6 b. Thehill 6 a forms an upper round surface to be in tangential contact with asurface of an upper slide member aimed at preventing free pivoting ofthe lever upwardly. An upside-down hill 6 c forms a lower round surface,mirroring said upper round surface 6 a, to be in tangential contact witha surface of a lower slide member (not shown) aimed at preventing freepivoting of the lever downwardly. The height of the rib body 5 (theheight being measured between the upper and lower surfaces 7 and 8 ofthe rib body 5 near its meeting area with the rib lever 3) is similar tothe max distance between the round surfaces 6 a and 6 c of the rib lever3. The depth of the valley 6 is preferably of the minimal value whichstill permits sufficient rotation of the canopy rib for approaching itsfully deployed position. A mirroring valley 9 fulfills a similarfunction in the opposite rotation direction of the rib, i.e. permitssufficient rotation of the rib for approaching its fully closedposition. As can be appreciated the max thickness of the rib lever 3(measured e.g. along line 10 between the opposite flat walls of thelever) is certainly smaller comparing to the max distance between theround surfaces 6 a and 6 c of the rib lever. The round sliding surfaces6 a and 6 c of the rib lever are substantially planner in a directionparallel to the pivoting axis 11 of the rib. The pivot member 2 isformed as a pair of lateral protrusions from the lateral flat walls ofthe rib (only one is seen in this Figure) to form the pivoting axis fromthe same piece of material of the rib.

It can be appreciated that a distance between the pivot member 2 and thefree end of the rib lever 3 does not exceed about 200% of the maxdistance between the round surfaces 6 a and 6 c of the rib lever. Thepivoting member 2 has a diameter greater than about 20% of the riblever's length. Thus, the forces acting on the pivot members will bedispersed over a greater contact are between the pivot axis and theapertures in which it is situated, exerting reduced pressures. The freeend of the rib lever has a coin shape tapering towards the free end thusallowing to crowd together rib levers of a plurality of umbrella ribsclosest to the umbrella's centerline axis.

FIG. 6 illustrates the rib 1 of FIG. 5 with the free end of its riblever 3 situated in a slide 20 formed in a canopy conducting member 19constituted by upper and lower restricting members 21 and 22. In suchcanopy conducting member 19, the round surfaces 6 a and 6 c of the riblevers can slide when the ribs are forced to pivot upon a linearmovement of the conducting member in line with the longitudinal axis ofthe umbrella (i.e. as indicated by an arrow W).

As can be appreciated, the max distance between the rounded surfaces 6 aand 6 c is grater than the distance (measured as the diameter of atubular portion 23 of the restricting members 21 and 22) between slide'sportions which serve mirroring ribs. This is to emphasize how close tothe longitudinal centerline of the umbrella the rib levers may approach.It is appreciated that the tapering of the rib levers towards the freeends of the levers allows to crowd together the plurality of free endsof the rib levers in the very center of the umbrella, from above thestick.

According to the illustrated embodiment, the upper and lower restrictingmembers 21 and 22 are two exemplars of the same part formed from plasticmaterial and arranged to face one another to form the slide 20 inbetween. The parts are to be connected together by screw or boltinserted through a hole 24 and passing through inside the tubularportion 23 to secure the conducting member to the top edge of anactuation rod (not seen) passing through the stick.

FIG. 7 illustrates yet another embodiment of a rib according to thepresent invention. A rib 31 has a rib body 35 and a rib lever 33. Thefree end of the rib lever 33 has a coin shape truncated at the free end.It is to be noted that when the rib 31 is in a mid position betweenfully deployed and fully closed states of the umbrella, the free ends ofthe rib lever 33 reach their closest distance to the umbrella'scenterline axis. Therefore, by having the coin shaped free endtruncated, it becomes possible to locate the ribs 31 closer to thecenterline. The truncation does not affect the functionality of roundsurfaces 36 a and 36 c of the lever 33. Two mirroring ribs 31 aredepicted, the left one demonstrates the rib orientation in deployedstate of the umbrella while the right one demonstrates the riborientation in closed state of the umbrella. It should be understoodthat the configuration of FIG. 7 (i.e., different orientations of theribs) does not exist in a fully assembled umbrella, since they are allcorrelated by the canopy conducting member which govern theirorientation and movements.

FIG. 7 also illustrates, in a vertical cross section view, a base part40 of a housing in which the ribs are pivotally connected. The base part40 has a truncated conical profile, comprising a circular groove 41allowing connecting the housing on top of an umbrella stick, and aplurality of vertically oriented gaps 44 allowing the ribs to foldcloser to the stick. As can be appreciated, due to the location of therib pivot axis near a corner 39 between the rib body 35 and the riblever 33, the diameter of the umbrella in its folded state will notsignificantly exceed a diameter D of the housing measured at its widestregion.

FIG. 8 illustrates a top view of the ribs and the base part of thehousing illustrated by FIG. 7. Reference is made also to FIG. 10illustrating the base part in isometric view from above. The ribs 31 arepivotally connected to the umbrella's stick (not shown) through a ribhousing whose base part 40 is connected to the upper end of the stick.The pivot connection is by pairs of protrusions 32 made from both ribsides near the end of the rib body 35 to form a pivot axis 32. The pairsof protrusions 32 are situated in respective pairs of recesses 42 madein the rib holders 46 which in this example are formed as elevatedmembers of the base part 40. Each rib holder 46 contains two recesses 42each for receiving a respective protrusion 32 of an adjacent umbrellarib body 35.

A hexagonal tunnel 49 is formed in the bottom of the base part 40,through which an actuation rod (not shown) can emerge from the stick tojoin a canopy conducting member e.g. of the type 310 of FIG. 1, or 19 ofFIG. 6, to be accommodated within the housing.

For the purpose of description only, two of a total of eight umbrellaribs 31 are illustrated in this Figure, while spaces in the base part 40for receiving the six remaining ribs are illustrated empty. Each ribreceiving space in the base part 40 contains a gap 44 formed between tworib holders 46 which are base part members elevating from the housingcollar 58. The gaps 44 extend downwards the base part in order to allowthe ribs approaching near the stick when pivoting towards a closed stateof the umbrella.

The base part 40 further has bores 58 made in the top surface of the ribholders 46, for receiving corresponding protrusions made in the bottomof the cap 62 (illustrated by FIG. 9). The connection between the bores58 and the corresponding protrusions may be reinforced by screws eachpassing through a respective pair of protrusion and bore.

After the protrusions 32 of all the eight ribs are situated in therespective recesses with the free ends of the rib levers seating in theslides of the canopy conducting member, the housing cap 62 may beconnected to the base part as to secure the ribs by closing the recesses42 from above thus preventing escape of the protrusions 32 from therecesses 42.

FIG. 9 illustrates an isometric view of a cap 62, showing its bottom,which matches the top of the base part 40. The cap has pairs of recesses42 a, made in closures 46 a, each closure 46 a cooperates with acorresponding rib holder 46 such that when the base part is closed bythe cap, the recesses 42 made in the rib holders 42 and the recesses 42a made in closures 46 a form pairs of cylindrical spaces accommodatingrespective pairs of protrusions 32 of the umbrella ribs 31. It is to benoted that it is possible also to have recesses only in the rib holders46 of the base part provided that they are sufficiently deep so as toaccommodate the protrusions 32. In such a case the bottom of theclosures 46 a may be flat and yet keep the umbrella ribs closed betweenthe cap 62 and the base member 42. Protrusions 58 a are also beingformed in the bottom of the closures 46 a, and are matching the bores 58made in the rib holders 46 of the base part 40, so as to facilitateconnecting the cap on top of the base part. A gap 44 a is formed betweeneach pair of neighboring closures 46 a, forming extension to acorresponding gap 44 located between respective pair of neighboring ribholders 46, thus allowing the umbrella ribs to pivot between a fullydeployed state and a fully closed state.

FIG. 10 illustrates an isometric view of the base part 40 illustrated byFIG. 8.

FIG. 11 illustrates in isometric another embodiment of a two parthousing 150 connected on top of umbrella stick 139. Cap 162 of thehousing 140 is secured to base part 140, and eight umbrella ribs 131 arepivotally connected between the cap and the base part. Due to gaps 144formed between pairs of neighboring rib holders 146, the umbrella ribsmay be folded to lay juxtaposed the stick 139 when the umbrella isclosed. Thus, the diameter of the closed umbrella is determined by thediameter of the housing at its widest portion 180. The ribs 131 do notsignificantly influence the diameter of the closed umbrella, since theyare accommodated within the gaps. In this embodiment the cap 162 hasintegral threaded bolt protruding upwardly, useful for mounting aferrule.

Those skilled in the art will readily appreciate that variousmodifications and changes can be applied to the embodiment of theinvention as herein described without departing from its scope definedin and by the appended claims.

1. Umbrella rib assembly for use in strutless umbrella having a pin andslide canopy conducting mechanism, the rib assembly comprising alongitudinal rib body having a pivot member at its end, and a rib leverextending from the rib body, and being characterized in that the pivotmember is located in a corner formed between the rib body and the riblever.
 2. The rib assembly of claim 1, wherein the rib lever extendsfrom the rib body in an angle of between 110-160 degrees.
 3. The ribassembly of claim 1, wherein the rib lever has a goggles shaped profile.4. The rib assembly of claim 1, wherein the rib lever of the rib bodyhas rounded upper and lower sliding surfaces, the height of the rib bodybeing similar to a maximal distance between said rounded surfaces. 5.The rib assembly of claim 1, wherein a maximal thickness of the riblever is smaller comparing to a maximal distance between rounded upperand lower sliding surfaces of the rib lever.
 6. The rib assembly ofclaim 1, wherein rounded upper and lower sliding surfaces of the riblever are substantially planner in a direction parallel to a pivotingaxis of the rib assembly.
 7. The rib assembly of claim 1, wherein thepivot member is formed as a pair of lateral protrusions protruding froma pivot point to form a pivoting axis from the same piece of material.8. The rib assembly of claim 1, wherein a distance between the pivotmember and the free end of the rib lever does not exceed about 200% ofthe maximal distance between round upper and lower sliding surfaces ofthe rib lever.
 9. The rib assembly of claim 1, wherein a free endportion of the rib lever has a coin shape tapering towards the free endof the rib lever.
 10. The rib assembly of claim 1, wherein a free endportion of the rib lever has a coin shape truncated at the free end ofthe rib lever.
 11. The rib assembly of claim 1, wherein the pivot memberhas a diameter greater than about 20% of the rib lever's length.
 12. Therib assembly of claim 1, wherein, formed from a polymeric material. 13.A strutless umbrella comprising a plurality of the rib assembliesaccording to claim
 1. 14. The umbrella of claim 13, wherein each of saidrib assemblies is pivotally mounted in a housing having a base partconnected on top of the umbrella's stick and a cap part secured on topof the base part, pairs of recesses being formed between the base partand the upper part each accommodating a pivot axis of one of the ribassemblies.
 15. The umbrella of claim 14, wherein the free ends of therib levers are located between upper and lower restricting membersforming a slide in which rounded upper and lower surface of the riblevers can slide when the rib assemblies are forced to pivot upon alinear movement of the slide in line with the longitudinal axis of theumbrella, the upper and lower restricting members being secured to eachother and to the upper edge of a rod passing through the stick, by meansof a screw.
 16. The umbrella of claim 14, wherein the free ends of therib levers are located between upper and lower restricting membersforming a slide in which rounded upper and lower surfaces of the riblevers can slide when the ribs are forced to pivot upon a linearmovement of the slide in line with the longitudinal axis of theumbrella, a distance between the round surfaces of the rib lever beinggreater than a distance between slides which serve mirroring ribs. 17.The umbrella of claim 13, wherein the rib assemblies have graduallyreduced thickness towards their distal ends resulting in flexibility ofthe ends of the rib assemblies useful for obtaining mushroom shapedcanopy.